RCR40 is finally on the road after just over 3 years build. Massive thanks to Chris Kouba, Ron McCall, Mahlon Miller, Dennis Quello, and so many others on this forum without which there is no way in hell this would be anything more than a pile of bolts at this point.
First few drives have involved major carburetion issues as fuel sat in the floats for over a year between when the engine was complete/dynoed and when we finally got it in the car and running. So after a thorough disassembly and cleaning of the jets and passages, it is running well throughout the power range. Setup is 4x 48IDA Webers, put together by Jim Inglese, and a 363 small block ford (Dart block) put together by Craft Performance Engines in Arkansas. Jim Inglese spec'ed the cam and intake manifold and set up the float heights as well as custom jetting for this specific engine. Fuel pressure is set to 2.5 psi per Jim's instructions.
Cold starts are fine -- two shots of throttle and it starts up fairly easily. But once the engine has been warmed up, it won't restart when shut off and it takes 45 minutes to an hour of cooling down before it will start again. I can hear fuel bubbling in the carbs and a stream of fuel drips out of the accelerator pump jets onto the throttle plates ever few seconds for up to 25 minutes after shut down. This happens even when I have shut the fuel pump off well before shutting off the car and the fuel pressure is reading zero. In fact, pulling the tops off the carbs doesn't stop the fuel from dripping out of the pump jets into the venturis with no new fuel coming in.
Clearly, my inability to restart the car when hot is due to this flooded state, but what is the solution? I have tried wrapping the fuel lines in heat sleeves with no effect. Using an infrared thermometer, the carb bodies are reading about 140-150 degrees F with the top of the intake manifold beneath about 200 degrees. Is this hot enough to boil the fuel?
I want to avoid the "turkey pan" if possible and considering phenolic spacers under the carbs as a next step. Any ideas are appreciated. Today's drive ended up in a tail pipe fire that had me scrambling for the fire extinguisher but thankfully burned itself out after a few seconds. Not wanting to drive more until this is under control!
First few drives have involved major carburetion issues as fuel sat in the floats for over a year between when the engine was complete/dynoed and when we finally got it in the car and running. So after a thorough disassembly and cleaning of the jets and passages, it is running well throughout the power range. Setup is 4x 48IDA Webers, put together by Jim Inglese, and a 363 small block ford (Dart block) put together by Craft Performance Engines in Arkansas. Jim Inglese spec'ed the cam and intake manifold and set up the float heights as well as custom jetting for this specific engine. Fuel pressure is set to 2.5 psi per Jim's instructions.
Cold starts are fine -- two shots of throttle and it starts up fairly easily. But once the engine has been warmed up, it won't restart when shut off and it takes 45 minutes to an hour of cooling down before it will start again. I can hear fuel bubbling in the carbs and a stream of fuel drips out of the accelerator pump jets onto the throttle plates ever few seconds for up to 25 minutes after shut down. This happens even when I have shut the fuel pump off well before shutting off the car and the fuel pressure is reading zero. In fact, pulling the tops off the carbs doesn't stop the fuel from dripping out of the pump jets into the venturis with no new fuel coming in.
Clearly, my inability to restart the car when hot is due to this flooded state, but what is the solution? I have tried wrapping the fuel lines in heat sleeves with no effect. Using an infrared thermometer, the carb bodies are reading about 140-150 degrees F with the top of the intake manifold beneath about 200 degrees. Is this hot enough to boil the fuel?
I want to avoid the "turkey pan" if possible and considering phenolic spacers under the carbs as a next step. Any ideas are appreciated. Today's drive ended up in a tail pipe fire that had me scrambling for the fire extinguisher but thankfully burned itself out after a few seconds. Not wanting to drive more until this is under control!
